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Array or List in Java. Which is faster?
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Effective Java recommends Lists for they help with API interoperability, and also more secure with type safety.
– juanmf
Dec 13 '14 at 15:04
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Is it expensive to use try-catch blocks even if an exception is never thrown?
...ork of setting up the try at runtime, the code's metadata is structured at compile time such that when an exception is thrown, it now does a relatively expensive operation of walking up the stack and seeing if any try blocks exist that would catch this exception. From a layman's perspective, try may...
【BLE技术内幕】BLE技术揭秘 - 创客硬件开发 - 清泛IT论坛，有思想、有深度
文章源自：http://doc.iotxx.com/index.php?title=BLE技术揭秘
BLE技术揭秘
BLE是低功耗蓝牙的英文缩写（Bluetooth Low Energy），是蓝牙4.0版本起开始支持的新的、低功耗版本的蓝牙技术规范。蓝牙技术联盟（Bluetooth SIG）在2010年发布了跨...
Correct way to use StringBuilder in SQL
...ard that string concatenation will use a StringBuilder under the covers if compiled with the Sun/Oracle compiler. This is true, it will use one StringBuilder for the overall expression. But it will use the default constructor, which means in the majority of cases, it will have to do a reallocation. ...
NumPy: function for simultaneous max() and min()
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With arrays, why is it the case that a[5] == 5[a]?
...+ 5), and from elementary school math we know those are equal (addition is commutative).
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Change MySQL default character set to UTF-8 in my.cnf?
Currently we are using the following commands in PHP to set the character set to UTF-8 in our application.
18 Answers
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How does a Java HashMap handle different objects with the same hash code?
...The hashmap will then look into the corresponding bucket, and then it will compare the key that you gave with the keys of all pairs in the bucket, by comparing them with equals().
Now you can see how this is very efficient for looking up key-value pairs in a map: by the hash code of the key the has...
Fast way of counting non-zero bits in positive integer
...t("1"). So if you can install gmpy, use that.
To answer a question in the comments, for bytes I'd use a lookup table. You can generate it at runtime:
counts = bytes(bin(x).count("1") for x in range(256)) # py2: use bytearray
Or just define it literally:
counts = (b'\x00\x01\x01\x02\x01\x02\x02...
Async image loading from url inside a UITableView cell - image changes to wrong image while scrollin
...SURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"http://myurl.com/%@.jpg", self.myJson[indexPath.row][@"movieId"]]];
NSURLSessionTask *task = [[NSURLSession sharedSession] dataTaskWithURL:url completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError *...